Rupert's drops -- Exploding glass.
"A Prince Rupert's Drop is so strong that you can hammer on one end without causing a crack, but watch out for the other endâ€”it breaks easily and causes the whole thing to explode!"
Markhttp://youtube.com/watch?v=8-GOwtikSO0

"This clip shows convection in a thin smectic liquid crystal film about 2mm wide and less than a micron thick. A voltage of a few volts is applied between the edges. The nonuniform thickness shows as colors that track the flow."http://tinyurl.com/ye74yd